Mordant Research Articles

Polarographic reduction of solochrome mordant dyes

In order to understand their redox behaviour, polarographic reduction of solochrome yellow 2GS, solochrome red ERS, solochrome black PVS and solochrome black WDFA at the DME was studied. All these dyes were found to give diffusion controlled irreversible waves. The kinetic parameters of these waves have been determined and a new empirical relationship between E1/2 and pH, viz. E1/2=0.063−0.031 pH±0.003 has been reported. A detailed mechanism indicating the effect of substituents on the E1/2 of these dyes has also been suggested.

Polarographic reduction of solochrome mordant dyes

In order to understand their redox behaviour, polarographic reduction of solochrome yellow 2GS, solochrome red ERS, solochrome black PVS and solochrome black WDFA at the DME was studied. All these dyes were found to give diffusion controlled irreversible waves. The kinetic parameters of these waves have been determined and a new empirical relationship between E 1/2 and pH, viz . E 1/2 =0.063−0.031 pH±0.003 has been reported. A detailed mechanism indicating the effect of substituents on the E 1/2 of these dyes has also been suggested.

Mercury-Free Raney Catalyst Method for Total Nitrogen in Fertilizers

Abstract The original Raney catalyst powder method for total nitrogen was shown not to be applicable to nitric phosphates containing non-sulfate sulfur. Interference by the non-sulfate sulfur was eliminated by the addition of morin, a mordant dye, before the reduction. The method was modified further by omitting HgO, a possible pollutant, from the digestion and by shortening the digestion time. The modified method is highly rugged for a considerable range of fertilizer materials.

Uranium(VI) complexes with mordant black dyes: spectrophotometric and potentiometric studies

Uranium(VI) complexes with mordant black dyes: spectrophotometric and potentiometric studies

A Mordant Judgment: J. C. Scaliger's Criticism of Lucan

A Mordant Judgment: J. C. Scaliger's Criticism of Lucan

Difficulties in ferrous iron mordant hematoxylin staining and some hematoxylin substitutes.

A gradual deterioration of intensity of sequence ferrous sulfate hematoxylin staining was traced, after elimination of hematoxylin quality as a cause, to a deterioration of the metal salt, associated with caking of the crystals. Fresh samples were also partly caked and ineffective. Ferrous ammonium sulfate was found also subject to the same deterioration. Ferrous chloride freshly prepared as a 1 M solution from iron wire under anaerobic conditions at biweekly intervals proved to be satisfactory as a mordant source. Of several other mordant dyes tested: gallein, brazilin and chromoxane pure blue B were the best, but none was equal to good hematoxylin.

Studies in chrome mordanting. VII.The nature of the chromium-dye complex formed during the chrome mordant dyeing of wool

When pre-chromed wool is immersed in a boiling solution of a mordant dye, the dye is rapidly absorbed by the wool. This is followed by a slower reaction in which the dye reacts with the chromium(111) in the wool to form either a 1 : 1 or a 1 : 2 chromium(111)-dye complex. With solo-chrome violet RS only a 1 : 2 complex could be detected in agreement with the results of earlier workers, but with solo-chromate fast red both 1 : 1 and 1 : 2 complexes were detected in the wool. The equilibrium [Cr(dye)L(H2O)2] + dye ←→ [Cr(dye)2] + L + 2H2O lies further to the right when L is a negatively charged ligand such as SO42- or F- than when L is a neutral ligand such as H2O. This accounts for the preferential formation of 1 : 2 complexes in wool, where L is a carboxylate ion. It is shown that on average 1 : 1 chromium(111)-dye complexes are bound to slightly more than one carboxyl group. An explanation is advanced for the higher wash-fastness of the 1 : 1 and 1 : 2 chromium(111)-dye complexes relative to the corresponding free dyes.

Vinylpyridine Rubber (PBR)-Filler Interactions. II.

Abstract This paper describes some reactions of vinylpyridine rubber with fillers. The work was done to learn if there is a chemical basis for the superior abrasion resistance of pyridine rubber treads. The results show that chemical factors are important when rubber-to-filler interaction is involved. The copolymerized pyridine groups of the rubber are absorbed readily onto the filler surface, especially when the pyridines are modified by complex formation with certain zinc salts or by conversion to pyridinium cation. Multiple adsorption generates a network. Those qualities associated with reinforcement are enhanced: viscosity (carbon black “stiffening”), “bound” rubber, electrical resistivity, modulus and resistance to tearing and to abrasion. The network bonds are, however, temperature dependent and can be erased by heating to 100° C. Adsorption of modified pyridines onto filler is like the mordant dyeing of fabrics. The pyridinium compound acts like a color “lake” adsorbed onto carbon black. Adsorption-bonding can be used to generate a portion of the modulus in sulfur-cured treads. For the same modulus, less sulfur is required, with a corresponding improvement in heat-aging.

Analytical methods involving chelation: Phenanthroline and O, O′-dihydroxyazo compounds as reagents

IN 1937 it was possible to gather all the available information on the chelate ring compounds into one long review article [l]. The classification of chelate ring compounds attempted in that paper is still pertinent, but in 1962 a thorough compilation of the knowledge of chelate ring chemistry would take the form of a volume or two of Beilstein or Gmelin, and no one has the time, nor the interest, nor the money to carry out the chore such a compilation would entail. Not that it isn’t needed nor that it would be of less than great utility. The phenomenon of chelate ring formation plays a part in surprisingly diverse fields : the tanning of leather, the mordant dyeing of cloth; the study of the stereochemistry of the metals; the sequestering of metal ions in solution and the ramifications of this into the softening of water, the preservation of foods and the inhibition of the catalytic activities of metal ions; the biological activity of such basic components of plant and animal life as chlorphyll, hemoglobin, vitamin Blz and the enzymes; and finally, in analytical chemistry in the action of organic precipitating and color forming reagents. The biological and analytical aspects, of course, come closest to medicine. That metals and those organic compounds which unite with them by chelation play a part in medicine is attested by this and other recent symposia. That the analytical chemist has been improving his own tools and operations by chelate ring forming compounds may not have been so evident. In the following discussion two fields of chelate ringanalytical chemistry are reviewed and the thesis argued that the clinical and medical professions have and will further benefit from what might appear a remote or even aloof branch of the chemical profession.

An Investigation of the Mechanism of Dyeing of Anodic Alumina Films with Acid Wool and Mordant Dyes

SummaryInorganic anions retard the dyeing of anionic dyes on anodic alumina films. The effect becomes more marked with increase in the valency of the inorganic or the dye anion, and it is attributed to repulsion between the inorganic and the dye anions at the surface and competition between them for ionic sites. Sulphate, such as sodium sulphate, is very effective in preventing dyeing of dyes with at least two sulphonate groups in the molecule, and phosphate is even more effective. The results support the hypothesis that the dyeing process is adsorption partly by ion exchange and partly by covalent bonding with aluminium atoms in the surface. The dye anions appear to be more readily exchangeable with sulphate ions when ion exchange adsorption takes place than when they are adsorbed by covalent bonds. Experiments with alizarin and its sulphonate show that mordant dyes are probably adsorbed as negatively charged ionic micelles of the dye-metal chelate complex. It is suggested that this is the mechanism by w...

15. Chemical and photochemical degradation of anthraquinone mordant dyes in methanol. Part I

The first page of this article is displayed as the abstract.

Experiments on the Action of Mordants: I. ‘Single-bath’ Mordant Dyeing

ABSTRACT Aluminium sulphate was chosen as the simplest mordant, and purpurine (1,2,4-hydroxyanthraquinone) as the simplest dye suitable for use in experiments with mordants. It was shown by a series of experiments that a solution containing about 16 atoms of aluminium to each molecule of purpurine has special properties. A section already dyed with an aluminium/purpurine solution till chromatin is dark and cytoplasm lightly tinged, is in equilibrium with such a solution : that is to say, it neither takes up more dye nor loses any part of what it already holds. If the proportion of dye to mordant is increased, the section will take up more of the dye ; if the proportion of the mordant to the dye is increased, the section will lose part or all of the dye it held. The experiments described in the paper, taken in conjunction with existing knowledge of the behaviour of aluminion ions in solution and of their capacity to form chelate compounds with anthraquinonoid dyes, afford a basis for the following theory of single-bath mordant dyeing by aluminium/purpurine. One purpurine ion chelates with one hydrated aluminium ion to form a complex ion with double positive charge; this is attracted to sites of negative charge in the tissues, such as the phosphoric groups of the nucleic acids. Electrostatic attraction is replaced by covalent bonds, resistant to solution by neutral ethanol. In extraction (‘differentiation’) by the mordant, the dye partitions itself between the tissue/mordant complex on one hand and the dissolved mordant on the other.

INTRODUCTION OF CHELATE BOND TO FIBER

In order to know the effect of chelate formation with Hg on the dyeing properties of wool, the energy of activation in the absorption of dyes by Hg treated wool is determined. The same process as in the case of the absorption of Hg with wool is employed. The dyeing process is considered to be divided into the following three steps (a) absorption of dyes on the surface of fiber, (b) the diffusion of the adsorbed dyes at the surface of fiber into the inner part of fiber, (c) chemical combination of dyes with metallic ions in fiber. The following relationship is found appliciable in this case:Where, x is reaction rate (the quantity of dyes absorbed by wool in a state is divided by the quantity of dyes absorbed at equibrium), t is time.It means that the diffusion of dyes in fiber is a rate determining step in this dyeing. From the above equation (1), (2) is obtained, andThe energy of activation is calculated from (4) belows, From the inclination of these straight lines and from the difference between log xt20 and log xt30, and between log xt30 and log xt50, the energy of activation is computed. Acid orange II, acidic dyes, and chrome methyl orange A, mordant dyes, are used.The energy of activation of the absorption of these dyes with the Hg treated wool was compared with that with non treated wool. For non-treated wool, E were found to be 7570 cal/mol between 20 and 30°C, and 9830 cal/mol between 30 and 50°C, for Acid orange II and 11800 cal/mol (20_??_30°C), 11150 cal/mol (30_??_50°C) for chrome orange A. For Hg treated wool, E were 10720_??_13500 cal/mol (20_??_30°C) and 19900 cal/mol (30_??_50°C) for Acid orange II, and 26000 cal/mol (20_??_30°C) and 22000 cal/mol (30_??_50°C) for Chrome Orange A.Using the above dyes, Hg treated wool needs much more energy than non-treated wool does.Cross linking formed during the chelation with Hg in wool and the change of the charge in wool may have some relations to the above results.

The Dyeing of Nylon with Acid and Mordant Dyes at High Temperatures

A study has been made of the stability of acid and chrome dyes in solution at temperatures above 100°c. The effects of an increase in dyeing temperature above 100°c. on the levelling of acid dyes and upon the rate of chroming of chrome dyes have also been determined. The results emphasise the importance of controlling the exhaustion of the dyebath during the dyeing of nylon and confirm the rapid rate of chroming above 100°c.

CHEMICAL STUDIES ON POLYVINYLALCOHOL FIBER

Polyvinylalcohol fiber which is mixed-spun with polyethyleneimine was acetalized with various aldehydes. The following results were obtained.(1) The degree of acetalization depends generally on the electron-attracting power of atomic group attached to the aldehyde group. If the aldehyde molecule, however, has bulky and complex structure, the acetalization proceeds with some difficulties.(2) Polyvinylalcohol fiber which is a mixed-spun with polyethyleneimine has very good property in dyeing with acid or acid mordant dye. Moreover, the elastic behaviour of the fiber is appreciably improved when hydrophobic atomic group is introduced to the fiber by acetalization.

INTRODUCTION OF CHELATE BOND TO FIBER

In order to know the effect of chelate formation with Hg on the dyeing properties of wool, the energy of activation in the absorption of dyes by Hg treated wool is determined. The same process as in the case of the absorption of Hg with wool is employed. The dyeing process is considered to be divided into the following three steps (a) absorption of dyes on the surface of fiber, (b) the diffusion of the adsorbed dyes at the surface of fiber into the inner part of fiber, (c) chemical combination of dyes with metallic ions in fiber. The following relationship is found appliciable in this case:Where, x is reaction rate (the quantity of dyes absorbed by wool in a state is divided by the quantity of dyes absorbed at equibrium), t is time.It means that the diffusion of dyes in fiber is a rate determining step in this dyeing. From the above equation (1), (2) is obtained, andThe energy of activation is calculated from (4) belows, From the inclination of these straight lines and from the difference between log xt20 and log xt30, and between log xt30 and log xt50, the energy of activation is computed. Acid orange II, acidic dyes, and chrome methyl orange A, mordant dyes, are used.The energy of activation of the absorption of these dyes with the Hg treated wool was compared with that with non treated wool. For non-treated wool, E were found to be 7570 cal/mol between 20 and 30°C, and 9830 cal/mol between 30 and 50°C, for Acid orange II and 11800 cal/mol (20_??_30°C), 11150 cal/mol (30_??_50°C) for chrome orange A. For Hg treated wool, E were 10720_??_13500 cal/mol (20_??_30°C) and 19900 cal/mol (30_??_50°C) for Acid orange II, and 26000 cal/mol (20_??_30°C) and 22000 cal/mol (30_??_50°C) for Chrome Orange A.Using the above dyes, Hg treated wool needs much more energy than non-treated wool does.Cross linking formed during the chelation with Hg in wool and the change of the charge in wool may have some relations to the above results.

Dyes and dyeing in ancient Mesopotamia

This journal article identifies Sumer as a center for the bleaching, dyeing and weaving of wool. According to accounts clothing was brightly colored and patterned. Variegated hues were obtained by substantive, vat and mordant dyes. Black was derived directly from iron oxide or from plants such as Cassia bark used with iron sulphate. Blue likely came from Indigo prepared perhaps with lime or potash. Woad may have been used. Saffron and Tumeric provided rarer yellow dyes. Red was favored in many shades. Sumerian and Akkadian texts refer to blood red, rose color and russet. Kermes is identified as one red dye. Murex brandaris and Murex arunculus yield purple. The dyeing process as practiced by the Mesopotamians is little known. Scant information is provided by the Talmud and from comparison with Babylonian tablets on tanning. Fat, alum and gall were used as mordants for tanning and dyeing. Thread or yarn was dyed in vats. These vats and winding bobbins are described from archaeological finds in Palestine. Wooden vats were likely used in Mesopotamia.

The pH Control of Acid and Chrome Dyeing II—Single‐bath Mordant Dyeing

Journal of the Society of Dyers and ColouristsVolume 68, Issue 2 p. 49-57 The pH Control of Acid and Chrome Dyeing II—Single-bath Mordant Dyeing G. H. Lister, G. H. Lister Research Laboratory Sandoz Products Ltd. Canal Road BradfordSearch for more papers by this author G. H. Lister, G. H. Lister Research Laboratory Sandoz Products Ltd. Canal Road BradfordSearch for more papers by this author First published: February 1952 https://doi.org/10.1111/j.1478-4408.1952.tb02747.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume68, Issue2February 1952Pages 49-57 RelatedInformation

Studies on the Authraquinone Mordant Dyestuffs

Studies on the Authraquinone Mordant Dyestuffs

Textile Industry and the University of Leeds

The report to the Clothworkers' Company of the Advisory Committee on the Departments of Textile Industries and Colour Chemistry and Dyeing, University of Leeds, 1945–46, pays a high tribute to the work of the late Prof. F. M. Rowe. No appointment has yet been made to the research fellowships in dyeing or in physical chemistry; but research workers of the Sisal Growers' Association have continued to be accommodated in the Dyeing Department. Dr. E. Race, in collaboration with Prof. Rowe and Prof. J. B. Speakman, established a new technique for examining the constitution of the dye-chromium complexes obtained when wool is dyed with chrome mordant dyes, and with Dr. C. B. Stevens commenced work on the kinetics of chromium dye complex formation, including a study of the rates of formation and heats of combustion of chromium complexes of a series of dyes. Dr. E. M. Hunt and Prof. F. M. Rowe completed an investigation to establish degradation processes for determining the constitution of indigoid, thioindigoid and related types of vat dyes in substance, and Mr. F. M. Smith commenced a similar investigation of triphenylmethane dyes. Derivatives of catechol have been prepared for examination as intermediates for dyes, and Dr. A. T. Peters has completed an investigation of derivatives of 3: 4-di-tert.-butyl-acenaphthene and derived indigoid dyes, and with Dr. R. J. Moualim commenced the preparation and orientation of a series of derivatives of 2-tert.-butyl-naphthalene. Although the entry of British students was seriously affected by the demands of national service, the total number was fully maintained by ex-Service students and students from abroad, and the number of students in the Department of Textile Industries caused serious overcrowding.